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Rained Dec. 20,1927.

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PATENT OFFICE.

ASSIGNOB '10 PBODOB IABBIQUE DE 01 GENEVA, SWITZERLAND.

BITUMINOUS CONCRETE AND LIKE COMPOSITION.

Io Drawing. Original No. 1,558,408, dated September 1, 1925, Serial No. 740,299, filed September 27; 1924.

Application for reissue filed April 20, 1927. Serial No. 188,818.

This invention relates to concrete or like com sitions made under the action of heat as istinct from cement and like aqueous concretes but having mechanical properties 5 similar to cement concrete and retaining these properties under temperature conditions of use as distinct from plastic mastic com ositions. v Tlie invention in brief consists in aprocess for the manufacture of bituminous concretes which comprises the incorporation of" a graded minera or like aggregate Wlth a naturally occurrin bitumen used "m a su tably hard form, e words hard form in this specification and claim meaning that the naturally occurring bitumen is not to be softened or cut by the addition of oil or a flux, which softenin is commonly used when a mastic 'to rep ace an asphalt 18 required. Such mixture of bitumen and 011 is quite unsuitable for purposes of the present invention.

In carrying the invention into effect in one form by way of example applied to the manufacture of' an acid resisting vat or the lining for an acid resisting vat, a composition is made of the following materials in substantially the proportions specified Parts.

' Gilsonite 100 .These proportions I recommend but they may be varied and simple tests will serve' to slpw if any desired mixture is or is not suita e. s

The 'materials are suitably incorporated preferably under the action of heat, for example about 200-250 0., the powder being first incorporated with the melted or all filling materials mixed in at t e same time.

Bituminous compositions of the character dealt with herein when large surfaces come into question have a tendency to crack under sonite I comparatively large temperature changes unless means are taken to prevent this.

This is particularly the case when vats or other articlesof very large dimensions or irregular shape have to be made; when vats or other articles are submitted to very sudden orlarge variations of temperature. 7 To avoid this either ex ansion joints or reinforcements are required or both.

The jointing material is preferably an In this case the construction broadly speaking is that of an outer container formed of metal, wood, cement concrete or any other suitable material and a substantially separate inner container made of the new concrete. This inner container should be free to expand or contract within the outer container as far as may be necessary having regard to such expansion 'oints or reinforcement as may be employe in its construction and to the temperature changes to which it may be subjected.

For large tank linings broken stones up to about .25 mms. may conveniently be used or if the lining be thick up to 35 or 50 mms.

For the lining of large vats I have found it well to leave spaces of from 5 to 25 mms. at intervals of, sa l metres, these being filled in with a pliistic composition such as as halt.

n thecase of a digester 5 metres diameter by 7 metres high, I have used stones of the size of 15 mms. at the sides but on the top where the risk of cracking is greater I have employed stories up to 30 to 35 mms.

The invention may be em loyed in connec-' tion with road work in w ich case similar remarks as toexpansion apply as with tanks and the like.

If the ground on which the bituminous concrete surface is to be laid permits the pitch concrete to slip-easily, for example if the ground he covered with gravel or sand, then the expansion joints may 'be wider apart, say from 5 to 15 metres or more.

The point to bear in mind is that any expansion either. of the surface or of the substrate may be freely taken up.

In general, the greater the quantity of mineral matter containedin the concrete and the less pitch, the wider apart may the ex- A pansion joints be placed.

tank is to be put so that an acid resisting aggregate will be chosen for a tank required to contain acids.

As regards the broken stones or like 'large mineral matter, this may be employed up to 75 mms. or even larger.

a The greater the risk of cracking the larger the size stones that should be employed.

Having now described my invention what I claim as new and desire to secure by Letters Patent is As a new composition of matter the following materials incorporated under the action ofheat in substantially the proportions specified v p Parts. Gilsonite 100 Acid resisting powder passing. a

sievenot coarser than about 600 meshes to the square centimetre 250-375 Vashed river sand passing a sieve having between 4 to 100 meshes to the square centimetre 250-500 Acid resisting broken stone of size from 3 to 15 mms. approximate diameter 250-500 name to this specification.

- MARCEL LEVY. 

